Here is ISIS's reach into North Africa

In this Thursday Jan. 29, 2015 file photo, a Kurdish peshmerga fighter fires a weapon towards positions of the Islamic State group who are 500 meters or half a mile away, overlooking the strategic town of Sinjar, northern Iraq. AP BEIRUT (AP) — The mass beheadings of Egyptian Christians by militants in Libya linked to the Islamic State group have thrown a spotlight on the threat the extremists pose beyond their heartland in Syria and Iraq, where they have established a self-declared proto-state. Militants in several countries — including Libya, Egypt, Algeria, Yemen and Saudi Arabia — have pledged allegiance to IS leader Abu Bakr al-Baghdadi, although the degree of coordination and operational planning between IS leadership and the group's affiliates remains unclear.

Here's a look at the Islamic State group's reach across North Africa, and how the extremists' growing presence is viewed across the Mediterranean Sea in Europe:

LIBYA

— The country has been in free-fall since the end of the civil war that ousted longtime dictator Moammar Gadhafi in 2011. Libya's elected government has relocated to the far eastern part of the country, while a loose alliance of militias have set up a rival government in the capital, Tripoli. Fighting between government forces and Islamic militias rages in the second largest city of Benghazi. Hundreds of thousands of people have been displaced, embassies have shuttered and diplomats have fled the country, along with hundreds of thousands of foreign laborers, many of them Egyptian.

Members of the Libyan pro-government forces, backed by locals, gather on a tank outside the Central Bank, near Benghazi port, January 21, 2015. REUTERS/Esam Omran Al-Fetori

This chaos has proven fertile ground for IS, which has received pledges of allegiance from several extremist factions in Libya. IS-affiliated groups divide the vast, oil-rich country of 6 million people into three regions: Tripoli, Barqa or Cyrenaica in the east, and Fazzan in the south. The interior minister of Libya's elected government, Omar al-Sinki, has said that al-Baghdadi appointed a Tunisian named Abu Talha to lead the IS faction in Tripoli. Al-Sinki also has said that the bulk of IS militants in Libya are Tunisian and Yemeni.

According to postings on jihadi web forums, groups claiming allegiance to IS control the coastal cities of Sirte and Darna, and have a presence in at least three other locales, including Tripoli and Benghazi, the birthplace of Libya's 2011 uprising. Egyptian warplanes struck suspected IS targets in Darna on Monday, following the killing of the 21 Coptic Christians.

Militants claiming allegiance to IS have battled Libyan troops in Benghazi, often using suicide bombers. Last month, fighters loyal to IS claimed responsibility for a deadly and complex attack on a hotel in Tripoli.

EGYPT Smoke rises as a house is blown up during a military operation by Egyptian security forces in the Egyptian city of Rafah, near the border with southern Gaza Strip November 3, 2014. Egypt began clearing residents from its border with the Gaza Strip last week to create a buffer zone following some of the worst anti-state violence since President Mohamed Mursi was overthrown last year. Smoke rises as a house is blown up during a military operation by Egyptian security forces in the Egyptian city of Rafah, near the border with southern Gaza Strip November 3, 2014. Egypt began clearing residents from its border with the Gaza Strip last week to create a buffer zone following some of the worst anti-state violence since President Mohamed Mursi was overthrown last year. REUTERS/Ibraheem Abu Mustafa

— The Egyptian government is battling a burgeoning insurgency centered in the strategic Sinai Peninsula, which borders Israel and the Gaza Strip. North Sinai has seen a spike in militant attacks against security forces, particularly after the military ousted Islamist President Mohammed Morsi in 2013. The area has been under a dusk-to-dawn curfew since October.

Some militants there have declared their allegiance to IS, with one such group calling itself Sinai Province of the Islamic State. It claimed responsibility for a sophisticated and multi-pronged set of attacks late last month on Egyptian military positions that killed 32 troops. Last October, another major attack killed more than 30 troops, and last month Sinai Province militants claimed responsibility for the capture and killing of a police captain.

Sinai Province, which grew out of the al-Qaida-inspired group known as Ansar Beit al-Maqdis, has not attacked civilians directly, although some have died as a result of its violence. Extremist groups in Sinai rely heavily on weapons smuggled across the porous desert border with Libya. Despite more than a year of massive military operations in northern Sinai, which have included home demolitions along the frontier, the government has not been able to stem a daily stream of militant attacks there.

ALGERIA AND TUNISIA

— The Islamic State group's successes in Syria have inspired a number of radical Islamist groups to splinter away from the dominant North African branch of al-Qaida, known as AQIM, and declare allegiance to al-Baghdadi. Most prominent has been the Algerian Soldiers of the Caliphate (Jund al-Khilafah) led by a veteran al-Qaida commander that kidnapped French hiker Herve Gourdel in September and then put out a video showing his beheading. Algeria unleashed a massive operation against the group last fall, and most of its known members have since been captured or killed.

In Tunisia, the radical Oqba ibn Nafaa brigade has long had good relations with AQIM, but has also issued statements in support of IS. More importantly, however, there has been a steady flow of Tunisian recruits to al-Baghdadi's group, most passing through Libya for training. Increasingly, they have stayed there and fought with an alliance of Islamist militias as well as the Islamic State, and report have emerged of several Tunisian "martyrs."

WHAT THREAT DOES THIS POSE TO EUROPE?

— European states have looked on with growing alarm as militants with links to IS have risen in prominence across North Africa. Italy, which is just 800 kilometers (500 miles) from the Libyan coast, has been perhaps the most concerned by the extremists' surge in Libya. Italian authorities fear that Islamic militants might slip into the country on Libya-based smuggling boats crowded with refugees and migrants from Syria, Africa and elsewhere. Italian Premier Matteo Renzi has even gone so far as to press for U.N. intervention to stem the violence in Libya. On Sunday, Italy repatriated by sea its personnel from its Tripoli embassy and advised other Italians, many of whom work in oil or construction businesses, to leave Libya.

Fears about the IS threat are also running high in France, which has seen more people join extremists in Syria and Iraq than any other European country. Some 1,400 French citizens or residents have been identified as linked to jihadi networks in recent years, hundreds of whom have traveled to Syria or Iraq, Prime Minister Manuel Valls said last week. French authorities are particularly concerned that IS-linked extremists will stage attacks at home, and are trying to toughen counterterrorism laws and tools to stop them.

A Frenchman who killed four people at a Paris kosher market last month, Amedy Coulibaly, claimed ties to IS, and the group said last week that Coulibaly's girlfriend has joined IS in Syria. Another Frenchman with ties to IS, Mehdi Nemmouche, is the chief suspect in a deadly attack on the Brussels Jewish Museum. IS in recent months has started a monthly online magazine in French and have released multiple online videos in French urging French Muslims to join jihad in the Mideast - and if they can't, to stage attacks at home.